using System.IO;
using System.Net;
private void button1_Click(object sender, EventArgs e)
{
string remoteFileUrl=@"http://img1.tebyan.net/big/1393/05/10815525515518876156213521208177619316289.jpg";
string localFileName = @"C:\someImage.jpg";
WebClient webClient = new WebClient();
webClient.DownloadFile(remoteFileUrl, localFileName);
StreamWriter wr = new StreamWriter(localFileName);
wr.WriteLine("salam");
wr.Close();
}